Peripheral feed breaker



Aug. 30, 1960 o. DANYLUKE PERIPHERAL FEED BREAKER 2 Sheets-Sheet 1 FiledMay 1, 1958 0 0 0 0 0 0 0 0 Q 0 Q 0 0 0 O0 0 0 0 0 O 0 0 0 0 E 0 0 u 0O00000 0.000 00 QOQODOOUOOQOOO 00000000000000 0 0 0 0 V O 0 Q 0 O 0 0 V0Aug. 30, 1960 o DANYLUKE PERIPHERAL FEED BREAKER 2 Sheets-Sheet 2 FiledMay 1, 1958 INVENTOR. 052%; fiazyjme, BY Ma ATTORNEYS.

rERIPrm FEED BREAKER Ostap Danyluke, Newtown Square, Pa., assignor toBath Iron Works Corporation, Bath, Maine, a corporation of Maine FiledMay 1, 1958, Ser. No. 732,400

Claims. (Cl. 241-91) This invention relates to improvements in aperipheral feed breaker, and more particularly concerns a peripheralfeed breaker of the Bradford type.

Peripheral feed breakers heretofore proposed have included a rotatablecenter feed chute for feeding the material to be broken (for example,coal) into rotatable drums which are positioned on both sides of thecenter feed chute. The drums broke the coal into the required size andpassed them into an exit chute that led to a receiving hopper. However,some of the coal, instead of passing into the breaker drums, bypassedthe breaker drums and spilled directly through the center feed chuteinto the exit chute. This passes oversize particles into the exit chuteand is objectionable even though it may be only up to 3 percent of thematerial passing through the breaker.

Accordingly, it is an object to overcome the aforementioneddisadvantages, and to prevent oversize particles of spillage whichpasses through the center feed chute from passing into the exit chute.

It is another object to gather up the spillage and drop it back into thecenter feed chute for distribution to the breaker drums.

It is another object of this invention to drop the spillage at a pointof center feed chute travel within the quadrant defined by a horizontaland a vertical plane passing through the axis of rotation of the centerfeed chute. In other words, as the center feed chute rotates clockwise,the spillage is dropped at a point of rotation between 9 oclock and 12oclock.

Other objects and advantages of this invention, including the ease withwhich it may be adapted for use with existing equipment, will furtherbecome apparent hereinafter and in the drawings, in which:

Fig. l is a sectional view in elevation of 2. Bradford type breakerconstructed in accordance with this invention; and

Fig. 2 is a staggered sectional view of the breaker shown in Fig. 1generally taken as indicated by the lines and arrows II-Ii which appearin Fig. 1.

In describing the preferred embodiment of the invention illustrated inthe drawings, specific terminology will be resorted to for the sake ofclarity. However, it is not intended to be limited to the specific termsso selected, and it is to be understood that each specific term includesall technical equivalents which operate in a similar manner toaccomplish a similar purpose.

Turning now to the specific embodiment of the invention selected forillustration in the drawings, 'there is shown a Bradford type breakerfor breaking friable material into particles no larger than a desiredsize, which breaker includes an outer casing 11, peripheral feed chutes12 and 13, a rotatable drum 14 supported in casing 11 and provided withdrum sections 15 and 16, a centrally located and rotatable center feedchute 17, a shroud 18 positioned around and rotatable with the centerfeed chute 17, and an exit chute 19 formed in casing 11 below drum 14.

The friable material which is to be broken into particles A 2.9mmPatented Aug. 30, 1960 no larger than a desired size is passed into thebreaker through peripheral feed chutes 12 and 13 and is dropped intodrum sections 15 and 16 by center feed chute 17. The material is brokenin drum sections 15 and 16 by being repeatedly lifted by the internallifting shelves and dropped on the screens 26 and particles nolargerthan the desired size fall through the drum 14 into exit chute 1%. Theshroud 18 prevents particles of material which pass directly throughcenter feed chute 17 without being dropped into the rotatable drum 14from passing directly into exit chute 19, as is hereinafter more fullydescribed.

Outer casing 11 is provided with a hump section 22 which fits closelyaround the upper half of shroud 18 in order to contain the particlesgathered up by shroud 18 Within the shroud. Drum 14 is provided withhubs 23, 24 which are rotatably supported, and is driven by sprocket 25.Drum 14 is provided with screens 26 which have perforations 27 formedtherein, and it is through these perforations 27 that the particles nolarger than the desired size pass into exit chute 19.

Center feed chute 17 includes a hub 31, guide plates 32, 33, 34, and 35,and partition plates 36. Guide plates 3235 are arranged alternately todirect the material, for example, first into drum section 15, then intodrum section 16, then into drum section 15, then into drum section 16,and so on. Center feed chute 17 also includes radial flanges 37 and 38,rail beams 41 which extend the length of drum 14, and rail beam guards42. For a more detailed discussion of the construction of the breakerincluding center feed chute 17, reference is made to my Patent No.2,708,075 for a Peripheral Feed Breaker which issued on May 10, 1955.The numbers of the patent correspond to the numbers here as follows(Fig. 3 in the patent compared to Fig. 2 here): patent number 74 is herenumber 36 on the left hand side of the drawing; patent number 70 is herenumber 35; patent number 69 is here number 32; patent number 65 is herenumber 36 on the right hand side of the drawing; patent number 68 ishere number 33; patent number 52 is here number 34; patent number 62 ishere number 31; patent number 56 is here number 37; patent number 37 ishere number 41; and patent number 55 is here number 38.

Shroud 18 includes a ring 43 with screen plates 44 in which are formedthe perforations 45. Positioned at each side of ring 43 are the shroudside walls 46 and 47. Ring 43 is connected to rail beam guards 42 ofcenter feed chute 17 by lift flights 48. Lift flights 48 are providedwith a centrally located support fin 51 and have a neckeddown position52 which aids in admitting the material from feed chutes 12 and 13 tocenter feed chute 17 by providing a larger passageway through which thematerial passes.

Fixed to the interior of casing 11 and positioned about the lower halfof shroud 18 are the confining plates 53, 54 which confine any spillagewhich passes directly through center feed chute 17, and directs suchspillage into shroud 18 while preventing it from passing directly intoexit chute 19.

Shroud 18 is also provided with smaller lift flights 55 which areaflixed to the inner surface of ring 43, but which are not atttachedto'center feed chute 17.

In operation, the drum 14 and the center feed chute 17 with its shroud18 are rotated. The friable material to be broken passes through theperipheral feed chutes 12 and 13, and falls into center feed chute 17through the opening provided between shroud side Walls 46, 47 and thecenter feed chute 17. The material is directed by guide plates 3235 intodrum sections 15 and 16 in an alternate fashion. However, some of theparticles of material instead of passing into drum sections 15 and 16pass directly through center feed chute 17. These particles, known asspillage, are prevented from passing through the exit chute 19 throughthe action of confining plates 53, 54 and the shroud 18. Theperforations 45 of the screen plates 44in shroud ring 43 pass fines(particles which are no larger than the desired size) directly into exitchute 19, but .oversized particles of spillage are retained withinshroud 18 and are lifted by flights 48, 55 toward the peripheral feedchutes 12 and 13. When these spillage particles reach a point inrotation of flights 48, 55 within 90 of top dead center, the particlesof spillage are dropped into center feed chute 17 and directed into drumsections 15 and 16, and are dropped onto screen 26 of drum 14. Suchspillage thus rejoins the material which was originally directed intodrum sections 15 and 16 by center feed chute 17.

The shroud 18 prevents the spillage from passing through the rotatablecenter feed chute 17 into the exit chute 19, but passes the finesdirectly to exit chute 19 through the perforations 45 of the screenplates 44 in the shroud itself. Flights 48, 55 of shroud 18 rotate withit and breaker drum 14, and lift the spillage in the direction towardperipheral feed chutes 12, 13. The flights 48, 55 are positioned at anangle, preferably in the range of 30-45 degrees, away from a radiusdrawn from the axis of the center feed chute 17, so that the spillageslides back into the rotatable central feed chute 17 and is dropped intodrum sections 15 and 16. The shroud 18 carries only oversize particlesof spillage, and passes fines through its screen plates 44 to exit chute19.

This breaker is designed to handle friable material (such as coal) whichcan be broken into particles by dropping the material onto a perforatedplate, and is particularly concerned with insuring that the particlesare no larger than a maximum desired size. The particles may be smallerin size, and dust-like particles (called fines) are no problem. The drum14 utilizes a screen which restricts the top size of the coal.

The necked down portion 52 of lift flights 48 allow for feeding thematerial to be broken through the peripheral feed chutes 12., 13 intothe rotatable center feed chute 17.

Confining plates 53, 54 cover the shroud 18 in the lower half of therotation path of the rotatable center feed chute 17, and serve thefunction of confining the spillage.

The spillage is confined in the upper half of center feed chute travelby the hump section 22 of outer casing 11.

The angle of the flights 48, 55 away from a radial line of the centerfeed chute 17, and the speed of rotation of shroud 18 are of importance.The angle of the flight is designed so that all of the spillage gatheredup by the flight is dropped from the flight before reaching the top ofthe breaker. The rotation speed of shroud 18 is slow enough thatcentrifugal force does not keep the spillage on the outer periphery ofthe shroud as it would do if the drum 14 were rotated too fast. On theother hand, the rotational speed of shroud 18 is fast enough that theparticles of spillage are carried up by the flight 48, 55 and do notmerely roll over the flights, never being carried more than 90 degreesfrom the bottom of the shroud 18. Unless the spillage particles arecarried more than 90 degrees from the bottom of the shroud, there is nodrop of the spillage particles onto the central feed chute 17.

Very satisfactory results have been obtained with a drum and center feedchute unit which is 25 feet 6 inches in axial length, the drum being 14feet in diameter. In this unit the center feed chute is 3 feet 6 inchesin axial length so that there remains 22 feet of screening length. Thedrum is rotated preferably in the range of 11 to 13 r.p.m. and theflights are positioned at an angle in the range of 30 to 45 degrees froma radial line of the drum.

It is to be understood that the form of the invention herein shown anddescribed is to be taken as a preferred embodiment. Various changes maybe made in the shape, size and arrangement of parts. Equivalent elementsmay be substituted for those described herein, parts may be reversed,and certain features of the invention may be utilized independently ofthe use of other features, all without departing from the spirit of theinvention or the scope of the subjoined claims.

Having thus described my invention, I claim:

1. A breaker for breaking friable material into particles no larger thana desired size, comprising a rotatable drum having a screen withperforations large enough to pass particles of a size up to andincluding said desired size; rotatable chute means for directing saidfriable material into said drum; said breaker having a peripheralpassage for admitting said friable material to said rotatable chutemeans; means forrning an exit chute for receiving the particles passingthrough the perforations of said drum; and shroud means rotatable withsaid drum preventing oversize particles of said friable material frompassing directly from the rotatable chute means to the exit chute, andmeans to lift and drop said oversize particles into said drum.

2. The breaker defined in claim 1, wherein said shroud means includeslift flight means positioned at an angle from the radius of said breakerwith their outermost ends ahead of their innermost ends in the directionof rotation of the drum for lifting and dropping said oversize particlesinto the drum as said shroud means is rotated.

3. The breaker defined in claim 1, wherein said shroud means includes aring spaced away from the periphery of said rotatable chute means, andlift flights connecting said ring to said rotatable chute means.

4. The breaker defined in claim 3, wherein said lift flights arepositioned at an angle from a radius of said rotatable chute in therange of 30 to 45 degrees with their outermost ends ahead of theirinnermost ends in the direction of rotation of the drum.

5. The breaker defined in claim 3, wherein both sides of said liftflights are provided with a necked-down portion positioned radiallyinward of the ends of the flights for allowing passage of the friablematerial to said rotatable chute means.

6. The breaker defined in claim 3, wherein said ring is provided withscreen plates in its periphery through which it passes fines to the exitchute means.

7. The breaker defined in claim 3, wherein said shroud means is providedwith a stationary confining plate positioned on each side of the lowerhalf of the travel path of the ring for preventing oversize particlesfrom passing into said exit chute means.

8. The breaker defined in claim 3, wherein said drum is 14 feet indiameter.

9. The breaker defined in claim 3, wherein said shroud ring is providedwith side walls extending inwardly toward the axis of rotation of saidbreaker.

10. The breaker defined in claim 9, wherein said breaker is providedwith an outer casing and said outer casing is formed about the ring andside Walls of said shroud means to keep said oversize particles withinsaid shroud means.

References Cited in the file of this patent UNITED STATES PATENTS143,745 Bradford Oct. 21, 1873 1,261,398 Janney Apr. 2, 1918 1,784,983Borton Dec. 16, 1930 2,708,075 Danyluke May 29, 1952, 2,853,244Plirnpton Sept. 23, 1958

